Exposição ao fungicida Cerconil WP®: efeitos sobre a reprodução em modelo experimental e estrutura química do látex de seringueira

Abstract

Brazil produces approximately 1% of natural rubber derived from rubber tree (Hevea brasiliensis) in the world, and Sao Paulo state is the major producer. The plantation of rubber tree might be stricken by fungal diseases, specially Antracnose. This fact requires the necessity of agriculture defenders as Cerconil WP®, composed by thiophanate methyl and chlorothalonil, one of the most used. Facing the large exposure to these compounds of workers and population that live near plantations, it is extremely important evaluate its possible toxicity and health impacts. Once that, the present work had as objective identify potential teratogenic effects and maternal toxicity of exposure to Cerconil WP® fungicide in different doses, using rat as an experimental model. Moreover, the study also aimed to identify effects of this fungicide on the chemistry structure latex of rubber tree, via Raman Spectroscopy. Therefore, Winstar female rats, adults and pregnant were divided into 4 experimental groups, that received 0 (control), 400 (EA), 800 (EB) or 1200mg/kg/day (EC) of Cerconil WP®, via gavage, from 6º to 15º gestational day (GD). In GD20, pregnant rats were euthanized and submitted to laparotomy for collection of uterus and maternal organs. The fetuses were collect, processed to skeletal and visceral analysis. Rats that were exposure to the fungicide presented clinical signs of toxicity. Reduction in weight evidenced in all groups in comparison to the Control group in GD12. Weight of maternal liver was lower in group EC than Control and histopathologic analysis of hepatic tissue presented areas of focal necrosis, inflammatory infiltrate, picnotic nuclei in hepatocytes and microvesicular fat degeneration areas moderated in groups EB and EC. The percentage of fetuses with adequate weight for gestational age was lower in groups EA and EB, in relation to the Control and EC groups. Porcentage of little fetuses increased in group EA, in relation to the other experimental groups, and in group EB in comparison to Control. In addition, there was an increase of total incidence of skeletal anomalies in groups exposure in relation to the control. Skeletal alterations observed in higher frequency were: decrease in esternal centres, absence of xiphoid process and caudal vertebrae, malformation of suppra-occiptal and reduction on number of anterior and metatarsus phalanges. Measures of Raman Spectroscopy (laser island of 514,5 nm, 25 seconds of exposure and 3 to 5 accumulations) did not show significant chemistry alterations on the latex exposure in vitro to 2g/L of Cerconil WP®. Results demonstrated that the oral exposure of pregnant rats to Cerconil WP®, during organogenesis, might affect on the embrio-fetal development and cause low toxicity to general maternal health. However, the molecular structure of latex exposed to the fungicide was not affect on the experimental study conditions.